Manufacture of dried wood pulp for transportation and sale



U iTEo STATES PATE T Orrrce.

STEPHEN M. ALLEN, OF DUXBURY, MASSACHUSETTS.

MANUFACTURE OF DRIED WOOD PULP FOR TRANSPORTATION AND SALE.

SPECIFICATION forming part of Letters Patent No. 244,417, dated July 19, 1881.

Application filed June 15, 1881. (No specimens.)

of preparing the same.

. In this invention I have overcome one of the greatest difficulties which has stood in the way of making wood pulp a regular article of commerceto wit, the necessity heretofore existing of shipping the pulp in wet sheets where the water in the pulp constitutes some sixty per cent.'of its whole bulk. This form of shipment has been necessary for two reasons: first, because it is very difficult to dry the thick pasteboard sheets of wood pulp, which are usually made at the mill and folded and packed in bales of about one hundred pounds; and, second, because if the sheets of the usual thickness are dried in the air or by means of dryin g-eylinders, the pulp becomes so caked or glued together by the albuminous or pitchy or starchy matter in the same that it is almost impossible to subdivide the individual fibrils again in acommon beating-engine at the papermill. Hence wood pulp has generally been sold in wet bales, which will work better in the machine, from the fact that the fibrils have not been set or stuck together, which would be the case if previously dried. The drying would be quite expensive also to the original manufacturer of the wood pulp, and the pulp is not so good as when used wet before drying. Moreover, besides the great loss in long shipments of wet wood pulp on account of the sixty per cent. water contained therein, there is danger of heating, and of thus discoloring the fiberin warm weather. If the wood pulp be run in thin sheets from the wet machine over heated drying-cylinders, the same evil results are produced which attend the dryi n gin thick sheets. The sudden contact of the pulp, when first ground and whi i l containipg thg s o lublei. alpfimlfious juices,with heated igpn e apbonin gs arenotagaineasilyseparatedbybeating. This invention overcomes all these difficulties.

When the pulp, either all wood or mixed with other fibers, is run off upon the wet machine, instead of letting it accumulate upon the surface of the roll, in the usual manner,

(board thickness,) to form a sheet before it is cut off, or, if in single thickness, letting it run off upon drying-cylinders, I introduce upon the face of the press-roll a brake or scraper, which clears the roll of pulp as fast as it accumulates from the feed in crimped folds or frills, and leaves it in the form of a porous body in a trough or upon an'apron, which may accumulate any convenient amountbf pulp, from twenty-five to one hundred pounds. The pulp, as soon as a bundle of sufficient size is formed, can be carried out to dry, or it may be run off upon aprons to proper places in the open air, or in a dry-house. In the latter case artificial head of moderate temperature is to be used.

The pulp is easily handled, can be dried without extreme heat, and without setting or earbonizingthe albuminons matter in the fiber.

It can then be baled and transported without having any dead weight, and when it is to be used the fibrils will, after soaking a few minutes in soft or warm water, disintegrate in a heater as well and as perfectly as though never dried. Such an article can be made a proper subject of commercial trade throughout the world without loss of freight, and with no danger of heating or molding.

In my Patent No.41,348, of January 19, 1864, for drying fibrous board and sheets the principle of drying fibrous substances by moderate heat by following up the laws of capillary attraction is described, and I have proved that that principle carried out in drying all kinds of fiber is a true one, and especially of great value to all vegetable fibers possessing gelatinous or albuminous substances in solution with the fiber. If dried gradually, the solutions do not coagulate; but if subject to sudden and great heat they become at once insoluble, and render fibers hard to separate, as well as brittle and stiff. This principle is utilized in this invention in drying the pulp. The sheet of pulp, as it comes from the roll of the machine, will be folded back and forth at short intervals in the direction of its length, and as it accumulates in the pit or upon the apron of its reception it forms a roll, or may be made into a mass of pulp convenient to handle, of any given size and shape, which will be as porous as a sponge, and will admit a current of air or heat through its whole body. No attempt is made to give a regular shape to these rolls of pulp, the object only being to accumulate a body of pulp that can be conveniently handled, and through which a current of air can circulate. One man and a boy can dry two tons of this fiber per day in the open air in good weather, and a dry-house in which currents of air are made to pass through the mass can easily be made to dry three times the amount.

Having thus fully described my said invention and the manner of carrying the same into effect, what I claim is- 1. The process or method of preparing pulp for transport by crimping and frillin g the sheets as they come from the machine, and afterward drying the same, substantially as described.

2. A crimped or frilled sheet of paper-pulp made, as described, from pure wood, or wood mixed with other fiber and dried, substantially as described.

3. Dried porous paper-pulp of wood fiber, or wood and other fiber mixed, said pulp containing the gelatinous or albuminous matters in a soluble condition, and being capable of ready disintegration, substantially as described.

In testimony whereof I have signed this specification in the presence of two subscribing witnesses.

STEPHEN M. ALLEN.

Witnesses:

HORACE G. ALLEN, ALICE E. WITHAN. 

